Direct Broadcast Receiving Station

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Direct Broadcast Receiving Station

• Craig Tapley
• DBRS Manager
• http//magic.tacc.utexas.edu/station/

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Facilities

• 2 X-band and 1 L-band antenna
• 3 independent GPS time systems
• 3 independent capture computers
• 3 primary processing systems
• 1 testing and support system
• 1 local visualization station

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Coverage
Coverage Area

• Excellent coverage of the lower 48 states
• Excellent coverage of the western Gulf
• Excellent coverage of Mexico and Central America
• Clear view of the horizon down to 0 degrees
  elevation
• Two x-band antennas resolve all current
  scheduling conflicts
• Single L-band antenna for near constant CHRPT and
  HRPT coverage

0 degree elevation coverage for Terra-1
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General system Status checking program(CheckStatu
s)

• General status checking program
• Intended to find and report error conditions
  across a network of mission critical systems
• Simple module additions allow customization for
  use in other locations

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CheckStatus Basic functions

• System IDs and e-mails start and end of any
  warning condition
• System can be programmed for any warning
  condition response
• Currently running on two magic DBRS systems on
  opposite half hour schedule

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CheckStatus Sample Module

• Check_noaa_status
• Uses wget (web information retrieval program) to
  retrieve current status of all active NOAA
  satellites
• Compares status to previous runs recorded status
• Sends warning e-mail message if there are any
  status changes
• Gives operator a heads up chance to change the
  capture priority if a change is needed

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Proclog

• QA system
• Human check of all data
• View thumbnails
• Add comments to specific images of interest
• Click view to see details of capture
• Sort by system, satellite, date, key word or
  primary capture designation

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Proclog

• Capture data screen
• Summary of all capture statistics
• Archive file locations
• Processing start times and durations
• Comments and warning messages
• Line error profile information
• Click view for more detail on processing or
  capture information

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Proclog

• Process detail screen
• Name and product ID for each process run on pass
  data
• Start and duration for each process
• Click view for more detail about each process
  run

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Proclog
All thumbnail images throughout the system can be
clicked for higher resolution view of the image
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Process Logging system (Proclog)

• Time and status of captures
• Antenna alignment info
• Percent of data captured
• Distribution of data errors
• Data processing times
• Reporting and graphing
• Specialized reports
• Special events and notes
• Human QA interface
• Web served interface

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Processor Optimization

• Stock Dell 8250 desktop servers
• 2.7 Gigabit processors
• 80 GB IDE 7200 RPM hard drive for raw data
  storage
• 120 GB IDE 7200 RMP hard drive for product
  storage
• MODIS and OCM test data base line numbers were
  gathered
• MODIS test data pass ran in 12937 (average over
  three trials)
• CPU usage averaged 21.8

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Processor Optimization Changes to configuration

• Lilo configuration was changed by adding
  Appendidebus66 ideoata66 to boot
  configuration to force hardware to operate at max
  available speed of the mother board
• Hard drives were split onto individual IDE chains
  to minimize data collisions and maximize I/O

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Processor Optimization MODIS results

• MODIS results
• LILO change decreased data processing time
  significantly
• Changes in IDE configuration also decreased data
  processing time.

IDE
Baseline
Lilo
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Processor Optimization OCM results

• OCM results
• Combination of LILO and IDE configuration changes
  made only small differences in total processing
  time

Baseline
LILO and IDE changes
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Processor Optimization Summary
MODIS
MODIS
OCM
OCM
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Auto-alignment System Overview

• Runs auto-alignment process daily using the
  following conditions
• Max and min sun elevation
• Clear time to next pass
• Length of alignment time
• Error collar ( 1001degree)
• First pass runs sunalign and checks if suggested
  correction is smaller than error collar
• If suggested corrections are less than the error
  collar alignment is repeated and results are
  accepted
• If suggested corrections are outside tolerance
  collar process is aborted and a warning messages
  is sent to the operator (or optionally some other
  action can be taken)

Adjustable alignment parameters
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Auto-alignment baseline antenna alignment

• Antenna holds alignment fairly well over time
• Some pointing slip is experienced over time
• Antenna takes successful pass captures even
  through the worst alignment period
• No clear indication of needed alignment without
  specific operator investigation

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Auto-alignment Auto alignment operating

• No operator attention needed
• Antenna reports any alignment issue outside of
  set collar
• Alignment is performed at the same time and
  elevation on most days allowing best alignment
  time and elevation to be repeated

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Auto-alignment Side by side views
Auto-alignment on
Auto-alignment off